It is the long-range purpose of this project to study the blood velocity profiles and hemodynamic stresses in the aorta and its major branches. The topics of present interest are: 1) a study of the geometry and elastic properties of the aorto-iliac junction to provide boundary conditions for detailed flow studies in this area; and 2) experimental validation of the nonlinear theory of pulse propagation to predict flow fields at more distal sites along the aorta from pressure-flow measurements made at a proximal site.